RIGHT-VENTRICULAR FUNCTION - PHYSIOLOGICA L AND PATHOPHYSIOLOGICAL FEATURES

Sinus and conus constitute the two cavities of the right ventricle. Th ey are anatomically and functionally different. The sinus is a flow-ge nerator and the conus a pressure-regulator. The coronary circulation o f the right ventricle is provided by the right coronary artery and the left anterior descending artery. The right ventricle is perfused duri ng systole and diastole. When oxygen demand increases, coronary arteri es dilate and oxygen extraction rises. As for the left ventricle, righ t ventricular performance depends upon heart rate, rhythm, contractili ty and loading conditions. Ventricular interactions are very important for right ventricular function. Loading conditions and contractility of the left ventricle are of major significance for right ventricular performance. For the right ventricle, the end of the ejection is diffe rent from the end of the active contraction. The time between them all ows to achieve ventricular emptying. This duration is linked to afterl oad. Presently, it is impossible to accurately and simply assess these conditions. Pressure and volume overloadings result in right ventricu lar failure. They are responsible for ventricular dilation and ischaem ia with a decrease in cardiac output, generating a vicious circle. Tre at ment includes the removal of the cause, and the maintenance of syst emic arterial pressure and biventricular contractility. It is difficul t to assess the effects of intravenous vasodilators on right ventricul ar afterload.